As is known, the forming of cardboard boxes is done by means of molds between which a sheet from which the box itself is obtained is placed in such a way that by means of an ascending/descending core the cardboard sheet is pushed against the mold, causing the forming of the box, the box being expelled when another cardboard sheet is placed upon the same mold to form another box.
The variation of dimension in the cores responsible for introducing the box inside the mold, can be said to be solved by some manufactures, and among them, the applicant firm itself, by using a core with a special structure and which is claimed in patent of invention Spanish application P-9200153 which corresponds to U.S. Pat. No. 5,256,129, having some extendible wings among other characteristics.
However, the adjustment of the size of molds has not yet been effectively solved and though mechanism tending to adjust the size of vary the dimensions of molds have been provided for, such mechanisms have the problem of malfunctioning, aside from the fact that they are based on very complex mechanisms.